For a wash process of a washing machine, the water level in the tub may be set based on the size of a fabric load and, sometimes, the fabric type of the fabric load, if this information is available. The more cost effective solution from a cost of the washing machine perspective is to have the user manually input the fabric load information through a user interface; although from the perspective of convenience to the user, it may be desirable to have the washing machine automatically determine this. For manual input by the user, the user may oftentimes overestimate or underestimate the load size, thereby resulting in too much or too little water, respectively, for the wash process. Too much water is wasteful, and too little water may lead to an insufficient wash performance and/or other negative implications.
Many methods are known for the washing machine to automatically determine the load size and/or fabric type, such as by employing an output of the motor that drives the drum within the tub and the agitator within the drum. However, these systems depend on additional motor sensors, such as motor torque, and the associated hardware, such as multiple or variable speed motors, and their electronics, such as the motor controller, which naturally increase the cost of the machine. These associated additional costs are often unacceptable. Therefore, many machines have motors that do not provide output useful for determining load size or have other limitations that preclude or make undesirable known methods for automatically determining load size.